This invention relates to filling containers, such as bottles with flowable substances. In particular the invention is directed to filling automatically containers with fluids which are flowable and range from viscous and thin to substances which readily form suds or foams.
The filling of such containers needs to be accurately effected, and for this purpose the filling mechanism should be easily adaptable to different kinds of fluids, changing working environments and conditions of the fluid, such as temperature. This is necessary so that an accurate control of fluid content where volume and weight are interrelated can be maintained. Small variations in the amount of fluid in different containers can amount to substantial aggregate variations and deficiencies where thousands of containers have been filled. Additionally each container can be inaccurate in its contents.
It is known to fill containers rapidly and accurately in a manner indicated in U.S. Pat. No. 3,870,089 (Laub III). In the system there disclosed, containers are fed onto a rotating turntable, and filled by nozzles. A cylinder has a piston and fluid in a cylinder from either side of the piston passes through a valve system into a respective nozzle filling the containers. The valve system operates under compressed air. There is thus a fluid system additional to the fluid supply for filling containers. This system is relatively complex and, due to the compressed air system, fairly noisy. Moreover, the cylinders and the respective pistons are not easy to adjust for different fluid conditions, weights and volumes of fluid and variations in containers.
In a further example of the prior art, namely U.S. Pat. No. 1,913,656 (Boyd) there is disclosed a filling machine for grease wherein the cylinder size is variable and thereby the volume of the cylinder is adjustable. A block is movable upwardly and downwardly by turning a screw. This adjustably limits the piston movement in the cylinder. The configuration of the cylinders and its adjustability is of a nature whereby precise adjustments for fluid flow from the cylinders into the containers is relatively difficult. Also there is a rotary valve operable with the cylinder which is relatively complex in operation and difficult to set for accurate filling.
In another example of the prior art, namely U.S. Pat. No. 3,419,053 (Tanner) there is disclosed a similar container filling machine. In this machine the cylinder volume is adjustable by having the end caps for the cylinders movable relative to the cylinder sleeve body. The valve mechanism operates with rotary valve devices in a manner which is relatively complex.
Another example of the prior art is U.S. Pat. No. 2,762,546 (Aidlin) which discloses an electric solenoid operated valve for effective charging and discharging of a cylinder. This system is also relatively complicated, and the piston structure and its rod connection hinders movement in the cylinder. No indication is given for adjustment.
There accordingly exists a need for a container filling machine which is easy to control and is accurate and consistent in performance and easily adjustable for different conditions and volumes.